<?php

if (!function_exists('http_build_url'))
{
	define('HTTP_URL_REPLACE', 1);				// Replace every part of the first URL when there's one of the second URL
	define('HTTP_URL_JOIN_PATH', 2);			// Join relative paths
	define('HTTP_URL_JOIN_QUERY', 4);			// Join query strings
	define('HTTP_URL_STRIP_USER', 8);			// Strip any user authentication information
	define('HTTP_URL_STRIP_PASS', 16);			// Strip any password authentication information
	define('HTTP_URL_STRIP_AUTH', 32);			// Strip any authentication information
	define('HTTP_URL_STRIP_PORT', 64);			// Strip explicit port numbers
	define('HTTP_URL_STRIP_PATH', 128);			// Strip complete path
	define('HTTP_URL_STRIP_QUERY', 256);		// Strip query string
	define('HTTP_URL_STRIP_FRAGMENT', 512);		// Strip any fragments (#identifier)
	define('HTTP_URL_STRIP_ALL', 1024);			// Strip anything but scheme and host
	
	// Build an URL
	// The parts of the second URL will be merged into the first according to the flags argument. 
	// 
	// @param	mixed			(Part(s) of) an URL in form of a string or associative array like parse_url() returns
	// @param	mixed			Same as the first argument
	// @param	int				A bitmask of binary or'ed HTTP_URL constants (Optional)HTTP_URL_REPLACE is the default
	// @param	array			If set, it will be filled with the parts of the composed url like parse_url() would return 
	function http_build_url($url, $parts=array(), $flags=HTTP_URL_REPLACE, &$new_url=false)
	{
		$keys = array('user','pass','port','path','query','fragment');
		
		// HTTP_URL_STRIP_ALL becomes all the HTTP_URL_STRIP_Xs
		if ($flags & HTTP_URL_STRIP_ALL)
		{
			$flags |= HTTP_URL_STRIP_USER;
			$flags |= HTTP_URL_STRIP_PASS;
			$flags |= HTTP_URL_STRIP_PORT;
			$flags |= HTTP_URL_STRIP_PATH;
			$flags |= HTTP_URL_STRIP_QUERY;
			$flags |= HTTP_URL_STRIP_FRAGMENT;
		}
		// HTTP_URL_STRIP_AUTH becomes HTTP_URL_STRIP_USER and HTTP_URL_STRIP_PASS
		else if ($flags & HTTP_URL_STRIP_AUTH)
		{
			$flags |= HTTP_URL_STRIP_USER;
			$flags |= HTTP_URL_STRIP_PASS;
		}
		
		// Parse the original URL
		$parse_url = parse_url($url);
		
		// Scheme and Host are always replaced
		if (isset($parts['scheme']))
			$parse_url['scheme'] = $parts['scheme'];
		if (isset($parts['host']))
			$parse_url['host'] = $parts['host'];
		
		// (If applicable) Replace the original URL with it's new parts
		if ($flags & HTTP_URL_REPLACE)
		{
			foreach ($keys as $key)
			{
				if (isset($parts[$key]))
					$parse_url[$key] = $parts[$key];
			}
		}
		else
		{
			// Join the original URL path with the new path
			if (isset($parts['path']) && ($flags & HTTP_URL_JOIN_PATH))
			{
				if (isset($parse_url['path']))
					$parse_url['path'] = rtrim(str_replace(basename($parse_url['path']), '', $parse_url['path']), '/') . '/' . ltrim($parts['path'], '/');
				else
					$parse_url['path'] = $parts['path'];
			}
			
			// Join the original query string with the new query string
			if (isset($parts['query']) && ($flags & HTTP_URL_JOIN_QUERY))
			{
				if (isset($parse_url['query']))
					$parse_url['query'] .= '&' . $parts['query'];
				else
					$parse_url['query'] = $parts['query'];
			}
		}
			
		// Strips all the applicable sections of the URL
		// Note: Scheme and Host are never stripped
		foreach ($keys as $key)
		{
			if ($flags & (int)constant('HTTP_URL_STRIP_' . strtoupper($key)))
				unset($parse_url[$key]);
		}
		
		
		$new_url = $parse_url;
		
		return 
			 ((isset($parse_url['scheme'])) ? $parse_url['scheme'] . '://' : '')
			.((isset($parse_url['user'])) ? $parse_url['user'] . ((isset($parse_url['pass'])) ? ':' . $parse_url['pass'] : '') .'@' : '')
			.((isset($parse_url['host'])) ? $parse_url['host'] : '')
			.((isset($parse_url['port'])) ? ':' . $parse_url['port'] : '')
			.((isset($parse_url['path'])) ? $parse_url['path'] : '')
			.((isset($parse_url['query'])) ? '?' . $parse_url['query'] : '')
			.((isset($parse_url['fragment'])) ? '#' . $parse_url['fragment'] : '')
		;
	}
}

function blg_parse_url($url){
	$parts= parse_url($url);
	$parts['query']= blg_parse_url_query($parts['query']);
	$parts['url']= $url;	
	return $parts;
}

function blg_build_url($parts){
	$parts['query']= blg_build_url_query($parts['query']); 	
	return http_build_url($parts['url'], $parts);
}

function blg_parse_url_query($query){
    $op = array(); 
    if(!empty($query)){
	    $pairs = explode("&", $query); 
	    foreach ($pairs as $pair) { 
	        list($k, $v) = array_map("urldecode", explode("=", $pair));
	        
	        $k= rtrim($k, '[]');
	        
	        if(!isset($op[$k])){
	        	$op[$k]= $v;
	        }elseif(!is_array($op[$k])){
	        	$op[$k]= array($op[$k], $v);	
	        }else{ 
	        	$op[$k][] = $v;
	        } 
	    } 
    }
    return $op;	
}

function blg_build_url_query($params){
	$query='';
	
	if(is_array($params) && !empty($params)){
		$str_params= array();
		foreach($params as $key => $val){
			if(is_array($val) && count($val)>1){
				foreach($val as $value)
					$str_params[]= $key.'[]'.(empty($value)?'':'='.urlencode($value));	
			}elseif(is_array($val) && count($val)==1){
				foreach($val as $value)
					$str_params[]= $key.(empty($value)?'':'='.urlencode($value));			
			}elseif(!is_array($val)){
				$str_params[]= $key.(empty($val)?'':'='.urlencode($val));				
			}
		}
		$query= implode('&', $str_params);	
	}
	
	return $query;
}


/*** ADD, DELETE, GET, CHANGE ***/

function blg_url_add_param($url, $param, $value){	
	$parts= blg_parse_url($url);
		
	if(!isset($parts['query'][$param])){
		$parts['query'][$param]= $value;
	}elseif(!is_array($parts['query'][$param])){
		$parts['query'][$param]= array($parts['query'][$param], $value);	
	}else{ 
		$parts['query'][$param][] = $value;
	}
	
	$url= blg_build_url($parts);	
	return $url;			
}

function blg_url_delete_param($url, $param){
	$parts= blg_parse_url($url);	
	unset($parts['query'][$param]);		
	$url= blg_build_url($parts);	
	return $url;	
}

function blg_url_get_param($url, $param){
	$parts= blg_parse_url($url);
	return $parts['query'][$param];
}

function blg_url_param_exists($url, $param){
	$parts= blg_parse_url($url);
	return (empty($parts['query'][$param])===FALSE);
}

function blg_url_change_param($url, $param, $value){
	$parts= blg_parse_url($url);
		
	$parts['query'][$param]= $value;
	
	$url= blg_build_url($parts);	
	return $url;	
}

function blg_url_append($url, $param, $value, $replace=FALSE){
	if(blg_url_param_exists($url, $param)){
		if($replace){
			$url= blg_url_delete_param($url, $param);
			$url= blg_url_add_param($url, $param, $value);
			return $url;
		}else{
			$old= blg_url_get_param($url, $param);
			$url= blg_url_delete_param($url, $param);
			$url= blg_url_add_param($url, $param, $old);
			$url= blg_url_add_param($url, $param, $value);
			return $url;			
		}
	}
	return blg_url_add_param($url, $param, $value);
}